Artificial hand and arm.



Patented Mar. 20, 5900.

H. SCHENK.

ARTIFICIAL HAND AND ARM.

(Application filed Apr. 19, 1899.) (No Model.)

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NITED STATES PATENT FFICE.

HENRY SOI-IENK, OF SANDUSKY, OHIO.

ARTIFICIAL HAND AND ARM.

SPECIFICATION forming part of Letters Patent No. 645,740, dated March20, 1900.

Application filed April 19,1899.

To all whom it may concern:

Be it known that I, HENRY SOHENK, a citizen of the United States,residing at Sandusky, in the county of Erie and State of Ohio, haveinvented certain new and useful Improvements in Artificial Hands andArms, of which the following is a specification, reference being hadtherein to the accompanying drawings.

My invention relates to artificial hands of that class in which arelative movement of the grasping'jaws is obtained by a connection withan elbow-lever.

The invention consists in the peculiar construction of a handcomprisinga rigid thumb and fingers movable in relation thereto;further, in the peculiar construction of the fingers and actuating meanstherefor, whereby difierent groups of fingers are independently movable,and, further, in the peculiar construction, arrangement, and combinationof parts, as more fully hereinafter described and claimed.

In the drawings, Figure 1 is a side elevation of my artificial hand asin use. Fig. 2 is an elevation of the hand looking toward the palm. Fig.3 is a sectional elevation showing the pivotal connections between thefingers and thumb, and Fig. 4 is a section at right angles thereto online 00 00.

A is the socket for the forearm, which is of any suitable construction,preferably comprising the metallic end cap a, the metallic side bars I),secured to said cap, and the sleeve 0, formed of leather or other softmaterial, adapted to be laced or otherwise secured to the arm.

B is the upper-arm section, comprising the side levers d, pivotallysecured to the bars I) opposite the elbow-joint of the arm, and theleather flap e, having the straps f for securing it to the arm.

To the lower end of the socket A is detachably secured the hand, whichis of the follow ing construction.

O is a head, preferably made of steel and provided with a pin or shankg, adapted to be swiveled in a socket formed centrally in the cap a.

h is a latch for holding the pin in its socket Serial No. 713,620. (Nomodel.)

which is connected to a knob or button t on the side of the socket andengages with the annular groove in the pin. I

The head O is provided with an extension D, which forms the core of thethumb E, the latter being formed in any suitable manner.

F and F are levers pivotally secured to the head O, upon opposite sidesthereof, by means of the bolt or pivot-pin G. These levers pass throughthe palm of the hand and are bifurcated, so as to form cores for thefour fingers, being bent into a hook shape, so as to give the appearanceto the hand of being partially closed. The hand and fingers arepreferably made of some soft material covering the skeleton frame andwith sufficient flexibility to permit of a limited independent movementof the levers. The outer ends of the levers are connected by the rods Hto the levers d of the upper-arm section a short distance above thepivotal connection with the rods 19. I

In operation when the hand is secured to the arm of the user and the armis bent at the elbow the rods H will move the lovers F F so as to carrythe fingers away from the thumb, as shown in full lines in Fig. 1. Inthis position the hand may be engaged with any object which could begrasped by the natural hand, and by a slight straightening of the armthe fingers are drawn toward the thumb, so as to firmly clamp thearticle.

Many articles, for grasping which the hand may be employed, are of sucha shape that were all the fingers to move together only one of themwould bear upon the article. To overcome this diffieulty, the levers Fand F may be moved differentially by giving the arm a slight twistingmovement at the same time that it is being straightened, or where anarticle is simply lifted the hand itself will swivel on the pin g into aposition where the pressure exerted by the two groups of fingers isequalized. Thus almost any ar ticle may be firmly grasped by thehand ina similar manner to that in which the natural hand would act.

The relative positions of the thumb and finger are such that when movedtogether the thumb will bear between the first and second fingers, bothof which are attached to the lever F. This enables the user to pick upvery small objects and to hold them firmly.

The actuating-arms of the levers F and F are concealed by the shieldI,which forms the upper portion of the thumb, and the rods H areconcealed by the coat-sleeve, so that the whole hand has a very naturaland life-like appearance and when gloved would scarcely be distinguishedfrom a natural hand.

In order to provide means for holding an article in the hand and at thesame time to permit of the free movement of the arm, I preferablyprovide the hook J, (shown in Fig. 3,) which is connected to the leversF and F and is adapted to be engaged with the side of the socket a, asshown in dotted lines, to lock said levers in a position in which thehand is closed. When this hook is so engaged,the hand will remain closedeven when the elbow is bent, these rods H being sufficiently flexible topermit of their bowing laterally without moving the levers F and F, or,if desired, said rods may be temporarily disconnected from the levers.When not in use, the hook J may be moved into the-position shown in fulllines, Fig. 3, Where it will not interfere with the operation of thelevers. The hook J is, preferably, slightly bowed to form a spring,which will permit of a slight yielding of the fingers when lockedby saidhook.

What I claim as my invention is- 1. In an artificial hand, thecombination with an arm-socket, of a rigid thumb secured thereto, and apalm member having permanently-hooked fingers movable toward or fromsaid thumb.

2. In an artificial hand, the combination with an arm-socket of a rigidthumb secured thereto, permanentlyhooked fingers pivotally secured tosaid socket, and means for moving said fingers differentially toward orfrom said thumb.

3. The combination, with the socket for the forearm and levers hingedthereto at the elbow upon opposite sides thereof, and secured to theupper arm, of a rigid thumb secured to said socket, two levers pivotedto and upon opposite sides of said thumb each bifurcated to formrespectively the first and second and the third and fourth fingers ofthe hand, and rods connecting the opposite ends of said leversrespectively to said opposite arm-levers.

4. An artificial hand comprising the head 0,- having the pin or shank gand the extension D forming the core of the thumb, the levers F Fpivoted to said head upon opposite sides thereof having hookedbifurcations and forming a skeleton for the palm and fingers of thehand, in combination with the socket A for the forearm in the end ofwhich said pin 9 is swiveled, the upper arm-levers cl pivoted to saidsocket at the elbow on opposite sides thereof, and rods I-I connectingsaid levers (1 respectively to the actuating-arms of the levers F and F.

5. In an artificial hand, the combination with thumb and finger membersone of which is movable in relation to the other, of a yielding elbowconnection for operating said movable member to open and close the handand a lock for holding the hand in its closed position against theaction of said elbow connection.

6. In an artificial hand the combination with thumb and finger membersone of which is movable in relation to the other, of a hook for lockingsaid movable member, in the closed position of the hand, and flexibleelbow-rods for normally operating said movable member by the elbowmovement of the arm, said rods being adapted to spring laterally whensaid hook is in engagement.

In testimony whereof I afiix my signature in presence of two witnesses.

HENRY SCHENK.

Witnesses:

M. B. ODocHEnrY, II. 0. SMITH.

